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>I need to add a new signal to a GTK+ widget. Any
idea?</A
></H1
><P
>If the signal you want to add may be beneficial for
other GTK+ users, you may want to submit a patch that
presents your changes. Check the tutorial for more
information about adding signals to a widget class.</P
><P
>If you don't think it is the case or if your patch is
not applied you'll have to use the
<TT
CLASS="LITERAL"
>gtk_object_class_user_signal_new</TT
>
function. <TT
CLASS="LITERAL"
>gtk_object_class_user_signal_new</TT
> allows you
to add a new signal to a predefined GTK+ widget without any
modification of the GTK+ source code. The new signal can be
emited with <TT
CLASS="LITERAL"
>gtk_signal_emit</TT
> and can be
handled in the same way as other signals.</P
><P
>Tim Janik posted this code snippet:</P
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>static guint signal_user_action = 0;

signal_user_action =
  gtk_object_class_user_signal_new (gtk_type_class (GTK_TYPE_WIDGET),
                    "user_action",
                    GTK_RUN_LAST | GTK_RUN_ACTION,
                    gtk_marshal_NONE__POINTER,
                    GTK_TYPE_NONE, 1,
                    GTK_TYPE_POINTER);

void
gtk_widget_user_action (GtkWidget *widget,
                        gpointer   act_data)
{
  g_return_if_fail (GTK_IS_WIDGET (widget));

  gtk_signal_emit (GTK_OBJECT (widget), signal_user_action, act_data);
}</PRE
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><P
>If you want your new signal to have more than the
classical gpointer parameter, you'll have to play with GTK+
marshallers.</P
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